Kluke Hi there, please make pics of the damage, serial nr and send it to the Dealer you bought it from -- he can then start a warranty process. Get the board fixed so it is water-tight in the meantime. When you get home you should be able to process the warranty as per normal.
The importer on Mauritius runs a fairly small Wingfoil business, so with all the import/freight costs he has, it is difficult for him to replace products bought elsewhere.
If the crack is on the top of the rail, which has been an issue on a small % of 2022 boards, then this is fairly easy to close up to make it watertight? (I have also seen some which are certainly not a production issue, rather user/boom/knee etc - in your case you mention normal use, understood). Good luck and enjoy the waves at Manawa etc, such a great spot!